Influence of process variables on the properties of simvastatin self-emulsifying granules obtained through high shear wet granulation

Improvements of the oral bioavailability of lipophilic drugs can be obtained using lipidic formulations such as the self-emulsifying drug delivery systems. The high shear wet granulation (HSWG), using microemulsions as binder, is a viable process to produce self-emulsifying granules. However only few information are present in the literature on the effect of process variables on the properties of the granules obtained with these binders. Consequently, this article compares the effects of some relevant experimental variables (impeller speed and massing time) on thefinal technological and pharmaceutical properties of the granules produced using simple water, or alternatively, a microemulsion as binder and containing simvastatin (SV) as model drug. The effects of the variables were determined by evaluating the granule median diameter, their particle size distribution, roundness, disintegration time and dissolution rate of SV. Results clearly demonstrated that the microemulsion-based process was less sensitive tooperating conditions than the water-based process. With microemulsion the nucleation process and growth regimes were more difficult to control, resulting in products with broader PSDs. At the same operatingconditions microemulsion-based granules were more brittle but rounder and showed smaller median diameter compared to water-based granules. The dissolution rate of simvastatin was not significantly affected by the operating conditions

Measurement on Different MLI Systems Between 77 K and 4 K and their Application in Cryogenic Engineering

Precise thermal measurements were done on different types of large surface MLI samples under various boundary conditions. The measurements were focused on the use of MLI for large industrial plants considering quick and simple installation. The results of the measurements aim at optimising MLI parameters, which control the thermal behaviour. Practical recommendations of MLI materials and their installation are given

PV cell angle optimization for energy generation-consumption matching in a solar powered cellular network

An inherent problem of solar-energy-powered-smallcell base stations (SBSs) is that the energy generation of the photovoltaic (PV) cell does not match the energy consumption of the SBS in time. In this paper, we propose to optimize the PV cell orientation angle to achieve a good match between the energy generation and consumption profiles on a daily time scale. The optimization is formulated as an integer linear programming problem. We also derive an expression for the correlation between the energy generation and consumption profiles to evaluate their general interaction independent of the exact PV cell or SBS deployment setup. The numerical evaluation of the proposed angle optimization in a business area in London in summer/winter shows that the optimal PV cell orientation in summer contradicts the conventional assumption of south facing being optimal in the northern hemisphere. Instead, a southwest orientation should be chosen in summer due to its ability to shift the energy generation peak towards the energy consumption peak in the afternoon at a SBS in central London. This is in accordance with the prediction given by our derived correlation between the solar energy generation and consumption profiles

UKRmol+: A suite for modelling electronic processes in molecules interacting with electrons, positrons and photons using the R-matrix method

UKRmol+ is a new implementation of the time-independent UK R-matrix electron-molecule scattering code. Key features of the implementation are the use of quantum chemistry codes such as Molpro to provide target molecular orbitals; the optional use of mixed Gaussian – B-spline basis functions to represent the continuum and improved configuration and Hamiltonian generation. The code is described, and examples covering electron collisions from a range of targets, positron collisions and photoionization are presented. The codes are freely available as a tarball from Zenodo

Impact of prolonged walking exercise on cardiac structure and function in cardiac patients versus healthy controls.

BACKGROUND AND DESIGN: Previous studies have demonstrated that endurance exercise can cause an acute transient decrease in cardiac function in healthy subjects. Whether this also occurs in cardiac patients is unknown. We investigated the impact of prolonged single day and three-day walking exercise on cardiac function and cardiac biomarkers between cardiac patients and healthy controls in an observational study. METHODS: We recruited 10 cardiac patients (nine males, one female, 68 ± 5 years) and 10 age- and sex-matched healthy control subjects (nine males, one female, 68 ± 4 years) to perform 30 or 40 km of walking exercise per day for three consecutive days. Cardiac function was examined using echocardiography and cardiac biomarkers (cardiac troponin and B-type natriuretic peptide) with blood samples. Data were collected before walking and directly after walking on day 1 and day 3. RESULTS: Post-exercise early systolic tissue contraction velocity of the left ventricle (p = 0.005) and global longitudinal left ventricle strain (P = 0.026) were increased in both groups compared with baseline. Post-exercise right ventricle peak early diastolic tissue filling velocity and systolic blood pressure/left ventricle end-systolic volume ratio decreased in both groups (p = 0.043 and p = 0.028, respectively). Post-exercise cardiac troponin levels increased (p = 0.045) but did not differ across groups (p = 0.60), whereas B-type natriuretic peptide levels did not change (p = 0.43). CONCLUSION: This study suggests that stable cardiac patients are capable of performing three days of prolonged walking exercise without clinically significant acute overall deterioration in cardiac function or more pronounced increase in cardiac biomarkers compared with healthy controls

Electron correlation and short-range dynamics in attosecond angular streaking

We employ the R matrix with time-dependence method to study attosecond angular streaking of F−. Using this negative ion, free of long-range Coulomb interactions, we elucidate the role of short-range electron correlation effects in an attoclock scheme. Through solution of the multielectron time-dependent Schrödinger equation, we aim to bridge the gap between experiments using multielectron targets, and one-electron theoretical approaches. We observe significant negative offset angles in the photoelectron momentum distributions, despite the short-range nature of the binding potential. We show that the offset angle is sensitive to the atomic structure description of the residual F atom. We also investigate the response of co- and counter-rotating electrons, and observe an angular separation in their emissio

UKRmol-scripts: a Perl-based system for the automated operation of the photoionization and electron/positron scattering suite UKRmol+

UKRmol-scripts is a set of Perl scripts to automatically run the UKRmol+ codes, a complex software suite based on the R-matrix method to calculate fixed-nuclei photoionization and electron- and positron-scattering for polyatomic molecules. Starting with several basic parameters, the scripts operatively produce all necessary input files and run all codes for electronic structure and scattering calculations as well as gather the more frequently required outputs. The scripts provide a simple way to run such calculations for many molecular geometries concurrently and collect the resulting data for easier post-processing and visualization. We describe the structure of the scripts and the input parameters as well as provide examples for photoionization and electron and positron collisions with molecules. The codes are freely available from Zenodo